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In motorcycle dynamics, great importance is attributed to the study of the weave and wobble vibration modes and, in particular, to the effects of the flexibility of structural components on their stability. Therefore, appropriate motorcycle models for studying weave and wobble should include flexible elements for describing the flexural behavior of components such as the main frame, front assembly, and rear swingarm. Different approaches are possible for modeling flexibilities: the most common among them are the lumped stiffness and the flexible multibody approaches. While the latter certainly provides higher accuracy, the former has advantages in terms of computational load, but, above all, it makes it easier to understand in the design phase how technical parameters, such as torsional and bending stiffness of a given structural component, can influence the stability of weave and wobble. The accuracy of lumped stiffness models strongly depends on parameter identification. In this study, a general method is proposed to determine appropriate lumped stiffness parameters for any given motorcycle component. The proposed method is tested and validated by comparing the weave and wobble modal behavior with the results of flexible multibody analysis. The lumped stiffness model is then adopted to carry out a sensitivity analysis aimed at identifying the effects on the weave and wobble stability of the torsional and bending stiffness of specific structural components of the motorcycle to optimize their design. [ABSTRACT FROM AUTHOR]

Fe3Al combines with steel to form bimetallic metal can benefit from steel's mechanical strength and make full use of Fe3Al's excellent performance under high temperatures. However, due to the poor fluidity and wettability of liquid Fe3Al to steel, the cladding prepared by traditional linear welding is not available to industrial sector. Hence, to optimize preparation, an arc deposition procedure based on a weaving path is proposed. Fe3Al cladding was prepared on the steel with weaving and linear paths by arc deposition technology, respectively, and the characteristics of the cladding were compared in terms of formability, surface feature and microstructure. The results demonstrated that the cladding prepared by weave arc deposition had better formability, lower dilution rates and fewer defects than that by the line one. Compared with the image captured by high-speed camera, the substantial difference was attributed to the higher molten pool velocities, which led to a smaller volume of molten pool in weave process. Under this circumstance, the arc force was conducive to the spread of liquid metal, forming a relatively small contact angle (< 45°). The finite element analysis revealed that the temperature distribution and thermal cycles resulted in finer grains in the weave process; furthermore, the weave process produced less residual stress, causing an increment of 153% in bonding strength between the cladding and the steel, compared to linear sample. Overall, the weave arc deposition technology is capable of molding Fe3Al layers efficiently and offers a good prospect for applications. [ABSTRACT FROM AUTHOR]

The Xinjiang region, with its unique location and climate, exhibits well-preserved relics of great academic interest. This paper focuses on the microinvasive analysis of textile samples obtained from an ancient turquoise mining site in the Heishanling region of Xinjiang, active between 820 and 400 BC. Various analytical techniques, including optical microscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy with attenuated total reflection, and liquid chromatography-mass spectrometry, were employed to investigate these textiles. The results revealed that the textiles were composed of wool and dyed using indigo and purpurin. The bluegrass and madder-derived dyes were likely sourced locally or imported from wetter regions such as the Chinese Central Plains. The infrared deconvolution spectra and the results demonstrated that red and blue dyes considerably influenced the movement of wool fiber chains, leading to a more rapid decay of dyed fibers compared to those that were undyed. In addition, the medium dyeing process and Ke techniques were employed to create unique color shades and special patterns. This scientific and technological analysis of the textiles provides essential data for elucidating the materials available to ancient laborers. Furthermore, it offers scientific evidence supporting the cultural exchange between the western regions and the Central Plains and integration along the Silk Road. [ABSTRACT FROM AUTHOR]

The strength properties of a flexible hose made of titanium carbide and having a weave not previously used for engineering purposes are studied. During the finite element modeling, it is shown that the hoses of the proposed design are able to withstand pressure, justifying their industrial application. At the same time, they are able to demonstrate a sufficiently high flexibility, nontraditional in the context of the mechanical properties of technical ceramics. This opens up new possibilities for using ceramics in science and technology. [ABSTRACT FROM AUTHOR]

This paper deals with the stability analysis of a novel four wheeled tilting motorcycle. This new kind of vehicle is equipped with two front steering wheels and two rear wheels; the front and rear suspension mechanisms allow the scooter to roll freely as a standard motorcycle. An analytical model of the vehicle with locked suspensions, rigid and lenticular tires was developed in order to study the stability of the system in straight running and to carry out a modal analysis focusing on the main normal modes. The frame and all the vehicle components were considered as rigid bodies, the driver was considered fixed to the frame and the tires behavior was described by a linear function of the camber and side-slip angles. The action of the driver on the handlebar was not taken into account, considering the vehicle running in straight without any control system. The stability analysis shows that the eigenmodes of the four-wheeler have several common features with the capsize, weave, wobble and rear wobble modes which characterize the dynamics of two and three wheeled motorcycles. A sensitivity analysis showing the influence of the front trail on stability and the vehicle eigenmodes is presented. A graphical and intuitive representation of the eigenvectors is also given. [ABSTRACT FROM AUTHOR]

Soldering the junctions in a novel woven structure constructed from metallic wires is expected to significantly enhance the mechanical properties of that structure. The ideal bond geometry has solder localized at wire junctions and a uniform amount of solder at each junction throughout the structure. By examining the effects of solvent variations, liquid flux concentration, and solder powder concentration on the soldered joint geometry and distribution, we have developed a new procedure to bond these wire junctions using a very fine solder powder suspended in a flux solution. [ABSTRACT FROM AUTHOR]

The last decade has seen several aspect language proposals for UML 2 sequence diagrams. Aspects allow the modeler to define crosscutting concerns of sequence diagrams and to have these woven with the sequence diagrams of a so-called base model, in order to create a woven model. In a real-world scenario, there may be multiple aspects applicable to the same base model. This raises the need to analyse the set of aspects to identify possible aspect interactions (dependencies and conflicts) between applications of aspects. We call a set of aspects terminating if they may not be applied infinitely many times for any given base model. Furthermore, we call a set of terminating aspects confluent, if they, for any given base model, always yield the same final result regardless of the order in which they are applied. Since confluence must hold for any base model, this is a much stronger result than many of the current approaches that have addressed detection of aspect interactions limited to a specific base model. Our aspects are specified using standard sequence diagrams with some extensions. In this paper, we present a confluence theory specialized for our highly expressive aspect language. For the most expressive aspects, we prove that confluence is undecidable. For another class of aspects with considerable expressiveness, we prescribe an algorithm to check confluence. This algorithm is based on what we call an extended critical pair analysis. These results are useful both for modelers and researchers working with sequence diagram aspects and for researchers wanting to establish a confluence theory for other aspect-oriented modelling or model transformation approaches. [ABSTRACT FROM AUTHOR]

This work illustrates the modelling aspects of an advanced motorcycle multibody model which captures the most important features of the vehicle, including five different suspensions schemes (telescopic fork, telelever, duolever, swingarm and paralever) all provided with their own flexibilities. Several lumped stiffness are used to model the structural compliance of the frame as well as the flexibility of the transmission system. A passive rider model which simulates the interaction of the rider with the handlebar and the chassis and a 3D road-tire model which takes into account both the carcass geometry and compliance are also included. The presented mathematical model performs non-linear time domain simulations, non-linear steady state analysis, linear stability and frequency domain analyses. Some simulation examples are presented: a steady state cornering manoeuvre where the decomposition of steering torque in its main components is carried out, a stability analysis where the effects of rider's impedance and structural flexibilities on weave and wobble vibration modes is highlighted, a stability analysis of a braking motorcycle which experiences a chatter instability and a lane change manoeuvre where the main handling indexes are computed. [ABSTRACT FROM AUTHOR]

The gray line-profile method is introduced to find fabric density. Some patterned fabrics like stripe design as well as solid fabrics of basic weave structures are used to verify the efficiency and accuracy of the method. The approach is compared with Fourier transform method. Although the gray line-profile method is concise, it shows good results in both solid and patterned fabrics. In addition, it does not require a pre-processing or filtering technique in space or frequency domain to enhance the image suitable for the analysis. However, the approach is slightly influenced by the filter size for finding the local minimums of profile graph. [ABSTRACT FROM AUTHOR]

Weaves are eigenstates of geometrical operators in nonperturbative quantum gravity, which approximate flat space (or other smooth geometries) at large scales. We describe two such states, which diagonalize the area as well as the volume operators. The existence of such states shows that some earlier worries about the difficulty of realizing kinematical states with non-vanishing volume can be overcome. We also show that the Q operator used in earlier work for extracting geometrical information from quantum states does not capture more information than the area and volume operators. [ABSTRACT FROM AUTHOR]